Jump-start a dead car battery
Check compatibility, connect jumper cables in order, and get help if the car still will not start.
Automotive · 20–30 min · Intermediate
Before you start
Work outdoors, clear of traffic. Stop for a damaged, leaking, swollen, frozen or hot battery, fuel odor, smoke, damaged cables or uncertain polarity. Never touch high-voltage components. Keep clamps separated and cables away from fans and belts. If either manual differs from this sequence, follow that vehicle’s procedure instead.
Tools and materials
- Vehicle-rated jumper cables
- Compatible donor vehicle
- Safety glasses and protective gloves
- Both vehicles’ owner’s manuals
Check the problem
Check whether a jump is appropriate
Dim lights or slow cranking can indicate low battery charge, but do not prove it. If the engine cranks normally without starting, or the car failed again after a recent jump, seek diagnosis rather than repeated jumps.
Identify the two systems and connection points
Read both manuals. Confirm compatible 12-volt negative-ground systems and that the donor is allowed to assist. Locate the designated positive points, donor negative point and disabled-vehicle ground. Do not choose points by their position in the picture.
Steps
Check both manuals and identify the jump points
Find the approved connection and starting procedure before opening terminal covers. Both vehicles must support the sequence below; otherwise use their specific procedure or roadside assistance.
Park close enough without touching
Set both parking brakes and select Park, or the manual’s specified gear. Switch off both engines and accessories. Secure the hoods and leave enough space to work safely.
Lay out all four clamps before connecting
Untangle the cables and keep all clamps apart. Route leads clear of fans, belts, hot surfaces, sharp edges and hood latches.
Connect red to the disabled vehicle positive
Attach one red clamp securely to its designated positive (+) point. Keep the other three clamps separated and away from metal.
Connect red to the donor positive
Attach the other red clamp to the donor’s designated positive (+) point. Keep both black clamps separated.
Connect black to the donor negative
Attach one black clamp to the donor’s designated negative (–) point. Keep the remaining black clamp controlled and away from metal.
Connect black to the designated remote ground
Attach the last black clamp to the disabled vehicle’s manual-designated grounding point, away from its battery. Do not use its battery negative post or copy the bolt shown in an illustration. Recheck polarity and cable clearance.
Follow the approved starting sequence
Use the manuals’ donor engine state, waiting interval and start-attempt limit. Do not invent an engine speed or repeat cranking. Stop for smoke, heat, arcing, abnormal odor or failure to start; arrange assistance.
Disconnect in reverse order and arrange a battery check
After a successful start, follow the manuals’ engine-state instructions. For this sequence, remove disabled ground, donor negative, donor positive, then disabled positive. Keep removed clamps apart. Stow the cables and arrange a battery and charging-system check.
The car starts, cables are removed safely and stowed, and persistent warning lights or repeat discharge are referred for diagnosis.
Tips
The donor need not be the same model
What matters is compatible systems and both manufacturers permitting the procedure—not matching badges.
Pictures are not a terminal-location map
Some vehicles use remote jump posts. Find the points in your manual before connecting anything.
Starting is not a battery-health test
A successful jump does not explain the discharge or prove the battery has recovered. Investigate warning lights, stalling or repeat failures.